Direct-current supply connector

ABSTRACT

A direct-current supply connector is disclosed comprising at least one pair of terminals for providing electrical connection between, on the one side of said connector an elongated flat module provided on the inside with low-inductance direct-current supply lines and, on the other side of said connector a module rack for receiving a plurality of said elongated modules. The module rack is connected with each of said modules over one of the connectors, current being supplied from said module rack to said module. A first individual pair section of said terminal pair which is connected to an outgoing line of the direct-current supply is connected with a second pair section of said terminal pair which is connected to a return line of the direct-current supply over a shunt capacitor disposed in the immediate vicinity of said connector thereby reducing interaction between elements in modules connected to one rack. The shunt capacitor may be located in the module rack or the module. It may be sized and connected to provide impedance matching between rack and module.

United States Patent [191 Menzel et al.

[ 1 June 10, 1975 1 1 DIRECT-CURRENT SUPPLY CONNECTOR [73] Assignee: Siemens Aktiengesellschaft, Munich,

Germany [22] Filed: Sept. 20, 1973 [21] Appl. No.: 399,336

[30] Foreign Application Priority'Data Sept. 22. 1972 Germany .j 2246602 [52] US. Cl 307/105; 317/101 DH; 325/357; 333/84 M [51] Int. Cl. H02j 1/02 [58] Field of Search..... 317/101 DH, 101 R, 101 C, 317/257; 339/176 MP; 333/84 M, 79; 325/472, 473, 474, 477, 493, 357; 307/185 [56] References Cited UNITED STATES PATENTS 2,421,780 6/1947 Frear 317/257 3,643,201 2/1972 Harwood 317/101 DH 3,651,432 3/1972 Hcnschen et al. 317/101 DH 3,702,422 11/1972 Schor 317/257 Primary ExaminerDavid Smith, Jr. Attorney, Agent, or Firm-Schuyler, Birch, Swindler, McKie & Beckett [57] ABSTRACT A direct-current supply connector is disclosed comprising at least one pair of terminals for providing electrical connection between, on the one side of said connector an elongated fiat module provided on the inside with low-inductance direct-current supply lines and, on the other side of said connector a module rack for receiving a plurality of said elongated modules. The module rack is connected with each of said modules over one of the connectors, current being supplied from said module rack to said module. A first individual pair section of said terminal pair which is connected to an outgoing line of the direct-current supply is connected with a second pair section of said terminal pair which is connected to a return line of the direct-current supply over a shunt capacitor disposed in the immediate vicinity of said connector thereby reducing interaction between elements in modules connected to one rack. The shunt capacitor may be located in the module rack or the module. It may be sized and connected to provide impedance matching between rack and module.

12 Claims, 3 Drawing Figures 1 DIRECT-CURRENT SUPPLY CONNECTOR BACKGROUND OF THE INVENTION The invention relates to a connector having terminals, e.g. pins and/or sockets for making electrical connections between, on the one side, an elongated module including a plurality of elements and, on the other, a module rack for receiving a plurality of such modules for direct-current supply. The connector within the scope of the invention is particularly suited for establishing connection between a flat module having plug pins or sockets and a module rack of an electronically controlled telephone switching system having sockets or plug pins.

A great variety of the above type of connectors for direct-current supply have been devised. Instead of plug pins and sockets, such connectors may also have clamped or soldered terminals or contacts pressed together, for example, by mechanical means.

All these types of terminals represent almost invariably spatially concentrated terminals, that is to say, terminals whose lengths, measured in the direction of the current, are substantially greater than their widths measured transversely of the direction of current. The module itself may likewise be designed in different ways, for example, as a flat module, more particularly as a multilayer flat module, that is to say, a largely threedimensional structure, e.g., a slide-in box or a substantially one-dimensional structure such as a long comparatively narrow body. All modules under consideration contain for the current supply a low-inductance outgoing circuit and a returncircuit.

The connectors for direct-current supply by themselves can basically also be designed as spatially unconcentrated structures, namely as strips whose lengths measured in the direction of current flow is substantially smaller than their widths or thicknesses measured transversely of the direction of current. Such a twodimensional terminal, compared with a spatially concentrated terminal, exhibits a comparatively low selfinductance, but requires considerable space, which is frequently undesirable, because generally in addition to the connector a multiplicity of additional terminals must be provided between the module and the module rack for the transmission of signals.

Strongly interfering voltages or voltage transients may be produced in the direct-current supply lines by switching elements disposed in or on the module. Such interfering voltages are generally the more disturbing the faster such interfering-voltage producing elements switch and the more sensitive such elements are to variations in the direct-current supply voltage. The interfering voltages produced propagate from the switching element over the module and possibly also over the module rack so that the direct-current supply of other elements can be considerably interfered with. Thus, these disturbing voltages must be avoided to the largest extent possible or at least their effects must be reduced.

Low inductance in the direct-current supply lines particularly those in a module, is required to reduce the effects of such interfering voltages, as explained in the publications Elektronische Rechenanlagen (1968), pages 177-179 and AEU 24 (1970), pages 263-268. However, the particular conditions in the connector have not been investigated. To reduce the harmful effects of this inductance the mounting of various high-capacity capacitors in specified places of the module was recommended in both printed publications with a view to reducing the harmful effects of said inductance. For example, in FIG. 7 of the first-mentioned publication it was recommended that on the module, approximately in the area of the connector, a single shunt capacitor be provided for each module over which the outgoing direct-current supply line is connected with the return direct-current supply line. Compare also the corresponding single shunt capacitor 10 with negligibly small internal resistance shown in FIG. 1 of the present application which is mounted on the module 2 in the vicinity of the connector 7. According to this prior art publication, the shunt capacitor 10 provided at this location shall be provided if the battery providing the direct-current supply is mounted at a great distance from the module or if the lines between battery and module, relative to high frequency operation, form too large a loop. Thus, the shunt capacitor serves here obviously for buffering a direct-current energy supply particularly so that the direct-current supply disturbed by crosstalk can be smoothed. In the other prior'art publication it is recommended that a high-capacity shunt capacitor be placed immediately at the direct-current supply inputs of each switching element, e.g. gates, provided on or in the module.

Modules that meet the demands made in the above identified printed publications with respect to the low inductance of the direct-current supply lines in the module are known in the art (see for example, FIGS. 10 and 11 of US. Pat. No. 3,300,686), where a multilayer flat module is described having two adjacent parallel two-dimensional conductors as direct-current supply lines. Thus, these conductors apparently provide strip conductors wherein the distance between the two lines is much smaller than the width of the conductors, as the width of the conductors can approximately equal the width of said module. Such strip conductors with extremely small distance/width ratios have, as is well known, an extremely small high frequency characteristic impedance and, thus, an extremely low selfinductance, at least as long as they are short in comparison with the wave length of the frequency components of the interfering voltages concerned.

SUMMARY OF THE INVENTION The present invention has as its basis recent investigations of the effects of such interfering voltages in the direct-current supply of modules. It has been discovered that in some cases where components mounted on different modules act upon each other concurrently, the low inductance of the current supply provided on the module is not adequate even with the mounting of a shunt capacitor 10 --cf. FIG. 1 of the present application in the vicinity of the connector 7 of the module to assure avoidance of breakdowns in the operation of such different modules with interacting components. The recent investigations (the details of which will be given hereinbelow) surprisingly demonstrate that in particular the self-inductance of the connector can also bring about serious breakdowns in the operation of the components. Based on this knowledge, it is another object of this invention to reduce the effects of the selfinductance of the direct-current supply terminals between the module and the module rack without considerably increasing the width or thickness of the individual terminals or requiring a great deal of space. In this connection, the teachings of this invention can even be applied to terminals which, for example, have already been made wide or thick for the purpose of reducing their self-inductance.

The invention takes as its starting point a directcurrent supply connector made up of terminals for electrical connection between, on the one side, an elongated module provided on the inside with lowinductance direct-current supply lines and, on the other, a module rack receiving a plurality of modules of the aforementioned type for direct-current supply. The connector according to the invention is characterized by the fact that between the module and the module rack there are provideda plurality of parallelconnected pairs ofterminals, of which each individual pair section of the first sort of the pairs of terminals which is connected to a direct-current supply outgoing line is connected with the pair section of the second sort of this pair of terminals over a shunt capacitor mounted'in the immediate vicinity thereof, said pair of terminals being connected to a direct-current supply return line.

BRIEF DESCRIPTION OF THE DRAWINGS The principles of the invention will be more readily understood by reference to the description of several embodiments given hereinbelow in conjunction with the accompanying drawings, wherein:

FIG. 1 shows an embodiment of the connector according to the invention between a module of the flat module type and a module rack;

FIG. 2 shows a special design of two adjacent pairs of terminals usable in forming a connector according to this invention; and

FIG. 3 is a circuit diagram illustrating the significance of the self-inductance of the connector on the dependable operation of components mounted on different modules and acting upon each other.

DESCRIPTION OF A PREFERRED EMBODIMENT First, let us examine the significance of the selfinductance of the connector: FIG. 3 shows two modules, viz. module 28 and module 2A, which are received by the module rack 8/9. To the direct-current supply lines 8 and 9 thereof are connected the earth potential and the supply voltage source. The switching elements, here gates 14, 16 and 18, are disposed on the module 28 and control similar elements mounted on other modules or are controlled by elements mounted on other modules. The two connectors of the directcurrent supply between the module rack 8/9 and the two modules 2B and 2A are each indicated by their self-inductances 11 and 13. There are additionally mounted on the module 2A the switching elements l5, l7 and 19 which are here controlled by the elements 14 and 18 mounted on the module 28 over the signal lines 20 and 21 or by other elements mounted on additional modules (cf. element 17). Therefore, here switching elements mounted on different modules act upon each other over the module rack 8/9.

This interaction, however, does not take place solely in the intended manner by virtue of the fact that the signals act as intended over the lines 20 and 21 on corresponding elements, but also indirectly in an unintended manner, because disturbances in the direct-current supply of such elements exercise an unintended influence.

Interfering voltages U U may appear over the self-inductances of the direct-current supply terminals, e. g. 11 or 13, if switching processes occur in the switching elements, e.g. 14 or 15 through which the currents in the direct-current supply lines 8 and/or 9 are changed. Depending on the size of the self-inductances 11 and 13 which frequently differ from one another and depending on the magnitude of the instantaneous values of the current variations through such selfinductances 11 and 13, interfering voltages U or U of different magnitudes appear in these selfinductances 11 and 13. These interfering voltages act I in the longitudinal direction of the direct-current supply lines. The amplitude of the interfering voltages depends on the particular magnitude of the selfinductance. The interfering voltages are thus particularly large if the self-inductance of the terminals is much larger than the self-inductance of the normally two-dimensional direct-current supply lines within the module.

The potential of one of the two direct-current supply lines, here the earth potential across the line 9, serves at the same time as a reference potential for the signals which are transmitted over the signal lines (cf. 20 and 21) from one module to the other. Interfering voltages which are superimposed upon the earth potential of the line 9 may lead to malfunctions of the elements provided on different modules, even if the well-known remedial step is followed of installing on the modules in the area of the direct-current supply terminals 11 and 13 low-inductance high capacity shunt capacitors 258 or 25A of which provide a short circuit for the interfering voltages there, but only there! This short circuit only prevents the voltage on the direct-current supply lines from being influenced by the interfering voltages U or U due to the self-inductances of the lines solely in its environment within the module. However, this short circuit on the shunt capacitor 253 and 25A cannot prevent the reference potential within one module 2B from being different from the reference potential on the module 2A due to the interfering voltages which normally differ from each other. The shunt capacitors 25B and 25A only prevent the interfering voltages U U from causing a change in the voltage between the direct-current supply lines within each module. The interaction of several elements mounted on one module which act upon each other only among themselves is thus not disturbed by the interfering voltages U U because the reference potential of the signals is equally large for all these components irrespective of the interfering voltages U U The situation is different if one considers the interaction between component parts mounted on different modules, because the signals transmitted on the signal lines 20 and 21 control the structural elements concerned in the intended manner only if the associated reference potentials of the interacting components do not differ too much from one another. Otherwise, disturbances may occur. Consider, for example, the following cases where the relevant reference potentials in the modules 2A and 2B are different for the interacting components due to the interfering voltages U and m.

Upon the switching of the component part l4 of the module 2B, there arises, for example, the interfering voltage U across the self-inductance 13in the connector of this module 28. If at the same time a signal is applied to the signal input of the component 16 of another module connected to the module rack 8/9, the interfering voltage U changes the signal voltage U controlling the component 16 to be switched. Therefore, if the interfering voltage U is sufficiently large, a false output pulse can appear at a signal output of the switching component 16, which in the last analysis, is caused by the self-inductance of the direct-current supply terminal 13 and by the different reference potentials .on the modules caused thereby.

Suchself-inductance '13 of a component 14 controlling another module may also produce disturbances in the-component 19 on the module 2A; for if the signal output of the component 18 is transmitted as an output signal over the signal line 21 to the component 19, whereas the interfering voltage U is generated across theself-inductance 13 due to switching processes in the other component 14, then this interfering voltage U exercises an influence upon the amplitude of the signal controlling the component 19. As a result, malfunctions of the component 19 may appear, because here, too, different reference potentials are caused on the modules 2A and 2B due to the self-inductance 13.

As indicated in FIG. 3, the self-inductance 13 of a component'15 controlled by another module may also interfere with the components 17 which are controlled in the relevant module 2A by signals which in themselves are received without disturbance by the other moduIeZB. This occurs when as a result of this signal controlling the component 15, there arise the interfervolta'ges U which influence the reference potential of the module 2A, which thereby may lead to disturbanc'es of the operation of the component 17 controlled by signals of another undisturbed module.

' Similar disturbances may arise as a result of the interaction between the components mounted on different modules if the self-inductance 11 of the direct-current supply line which does not carry the reference potential produces interfering voltages, because the shunt capacitors 25A and 258 for the interfering voltages within the modules produce short circuits influencing the reference potential. As a result the different components mountedthereat can be interfered with by disturbances of the potential of the direct-current supply line 8 as well as by the disturbances of the potential of the direct-current supply line 9. Hence, there is no basic difference with respect to the preceding discussion concerning effects of the disturbances of the reference potential, because the relevant shunt capacitors 25B and 25A connect the direct-current supply lines mounted in the module in parallel with one another at high frequencies.

It therefore can be seen that the commonly known remedial measures of installing one single high capacity shunt capacitor 25B and 25A (cf. the shunt capacitor shown in FIG. 1) on the module in the immediate vicinity of the direct-current supply thus prevents for the most part only the disturbances resulting from the interaction between structural elements which are installed on the module same. The commonly known remedial step, however, does not always prevent disturbances due to the interaction between the component parts which are placed on different modules even if a separate shunt capacitor is mounted on each of the relevant modules in the area, that is, in the vicinity, of its connector.

The improvement madeinaccordance with this invention is based on the requirements deduced from the above described investigation. It is necessary that the self-inductance of the connector shall be so reduced that no interfering voltages of high amplitude can appear there. To this end, according to th'ev invention, there are provided between the module 2 and the module frame 8/9 (cf. FIG. 1) a plurality of pairs of terminals 0 and 1 connected in parallel with one another-to the direct-current supply. Each pair of terminals contains a pair portion 1 and a pair portion 0 which lie so close together that they form a pair. The pair portion of the first kind 0 is connected to the outgoing line 6 of the direct-current supply of the module 2. The pair portion of the second kind 1 is connected to the return line 3 of the direct-current supply. The pair portion of the first kind 0 forms together with the closely adjoining pair portion of the second kind 1 a pair of terminals 7, so that the current forthe direct-current supply of the module 2 or of the component parts placed on said module can flow over the pair of terminals 7.

Due to the small distance between the terminals, the self-inductance of the terminals 0 and 1 is here, so to speak, reduced by increasing the self-inductance (cf. 5 in FIG. 2) so that the terminals represent a comparatively low-inductance line within the meaning of the high-frequency transmission line theory, instead of concentrated high inductances. v

Strictly speaking, the pairs of terminals 7 shown in FIG. 1 represent two pairs of terminals combined into a single pair of terminals (cf. FIG. 2 showing the two terminals of the first kind 0 and the terminal of the second kind 1 which together form a combined pair of terminals shown in FIG. 7.) The pair of combined terminals shown in FIG. 2 consists, strictly speaking, of two different simple pairs of terminals with the terminals 0 and 1, and 0 and 1a; however, the terminal la has been connected with the terminal 1, for the terminals 1 and 1a are here connected with the same return line of the direct-current supply.

Provision is made in the embodiment shown in FIG. 1 that each pair of terminals 7 (combined therein) is bridged by a single capacitor 25.

In the FIG. 1 embodiment the return line 3 of the direct-current supply is made up of three segments 3 running parallel to one another which can also be intermeshed with one another within the module, e.g., through the electrically conducting connections 30 between said segments 3 and shown in FIG. 1. Similarly, the outgoing line 6 can also be comprised of several segments; the segments of the outgoing line 6 may likewise be intermeshed with one another, just as the segments of the return line 3.

In the exemplary embodiment of FIG. 1, it has been assumed that not only are there provided several pairs of terminals 7 in the component part 2 for the directcurrent supply, but even several (namely 2) such (combined) pairs of terminals 7 for each segment 3 of said direct-current supply lines.

According to the invention (cf. FIG. 1), each individual pair portion of the first kind 0 of thepairs of terminals 7 is connected over a shunt capacitor, e.g. 25, disposed in the immediate vicinity thereof, with the pair portion of the second kind 1 of said pair of terminals.

In view of the fact that not only one pair of terminals, but several pairs of terminals are provided, the active self-inductance 11 or 13 (cf. FIG,. 7) of the terminals 7 between the direct-current supply lines 8 and 9 of the module rack andthe'direct-currentsupply lines 3 and 6 of the module has'a lowerin'ductance than if only a single such pair were provided. By widening the individual terminals or l of sa'id' pairs of terminals the self-inductance can further be reduced.

In view of the fact that a special shunt capacitor 25 is provided in each individual pair of terminals which bridges the two lines of the direct-current supply, the effects of the self-inductance of the connector are likewise reduced.

If instead of theplurality of shunt capacitors 25 only the single shunt'capacitor 10 disposed on the module 2 in the vicinity of the connector and having a negligibly small internal resistance (cf. FIG. 1) were provided, the considerable self-inductance of the lines 3,6 between the terminals 0,1 and said shunt capacitor 10, that is, the segment of the direct-current supply lines lying between the connector and the shunt capacitor, would virtually also have an operative effect as selfinductance of the connector 7. Since in each pair of terminals 7 a special shunt capacitor 25 is provided for the purpose of bridging the direct-current supply lines,

the series inductance between the terminals 0,1 and the relevant shunt capacitors 25 is practically completely eliminated so that the effects of the self-inductance in the connector is noticeably reduced by the plurality of shunt capacitors 25 disposed according to the invention.

In'a further development of the invention, provision is made that the terminals 0 carrying a signal reference potential, here earth potential (cf. also FIG. 3), are constructed with particularly low inductance.

FIG. 1 shows such a further development, where, in order to reduce the self-inductance of the terminals 0 carrying the reference potential, a plurality (here two terminals 0) are joined with a single terminal 1 into one (combined) pair of terminals. A further improvement of the low inductance of the terminals carrying the reference potential can also be realized by considerably widening the terminals 0.

Strictly speaking, in FIG. 1 the terminals 0 and 1 are made up of two connectors, namely the connectors 0,1 connected with the module 2, and the connectors 0,1 connected with the module rack. The terminal pins may, for example, be constructed as pins and sockets.

In the exemplary embodiment of FIG. 1, the shunt capacitors 25 are each disposed on the component parts of the terminals provided on the module 2, so that in general the expenditure in such shunt capacitors 25 can advantageously be reduced, because frequently the module rack will not receive the total number of modules it is capable of receiving. By way of example, it may be that not until some time after it is placed in use shall additional modules be received in the same module rack 8/9, when the telephone switching system having the module rack 8/9 is prepared for a larger number of additional telephone terminals to be connected. Since shunt capacitors 25 are only disposed in the modules that have already been received by the module rack 8/9, shunt capacitors 25 need not be associated with connectors of modules 2 to be received in the same module rack 8/9 perhaps at a much later period.

A further advantage is realized by these shunt capacitors 25: The signals transmitted in signal lines (cf. and 21 in FIG. 3) between various modules also produce briefly and frequently, depending on the particular construction of the switching elements, high currents in the self-inductance 11 or 13, particularly during the rise and fall times of'the signals, eg for charging the self-capacitances alongside the signal lines, and for charging the capacitances active in the components concerned. Such currents are particularly large if the component parts switch very rapidly. Thus, these currents produce short-duration interfering voltages in the self-inductances 11 or 13. The amplitude of these interfering voltages in the terminals can be reduced here by means of the shunt capacitor 25, since the latterproduces a short circuit for the relevantinterfering' voltages or charging currents for signal line capacitances, said short circuit connects in parallel the inductances 11 and 13. A similar process takes place in: the other, module, to which the signal line in question runs.,;Thus

also these parasitic voltages are reduced. by the. shunt components of the terminals 0,1 disposed on the mod-1 ule rack 8/9 are provided with shunt capacitors. Thus, instead of the shunt capacitors 25 or, preferably, in 'ad dition to these shunt capacitors 25, capacitors 24 arf provided as, for example, shown in FIG. 1. The reduc-' tion of the effects of the self-inductances of the directcurrent supply connector in this further development is mainly caused by the fact that the self-inductance in the area of transition from the pairs of terminals 7 to the direct-current supply lines 8 and 9 on the module rack 8/9 is neutralized 'mainly because this selfinductance of the junction can no longer have an effect as an interfering self-inductance at the connector. More often than not, this further development also has the advantage that space for the shunt capacitors 25 on the modules is now not absolutely necessary, so that on these modules still more components can be accommodated. Moreover, these shunt capacitors 24 when placedin addition to the shunt capacitors 25, reduce the above mentioned disturbing effects of charging currents for signal line capacitances through the self inductances 11 and 13 of the direct-current supply.

In the embodiment shown in FIGS. 1 and 2, the component parts of the terminals are plug pins or sockets, said components being urged against one another by their own elastic force. This further development is generally less complex than one in which the components of the terminals 0,1 disposed on the module are detachably urged by special means against the components of the terminals disposed on the module rack. The last-mentioned further development has, in turn, the advantage that an excellent electrical connection between the components of the terminals frequently can better be lastingly achieved than with plug pins and sockets, being independent of material changes, wear and tear and manufacturing tolerances.

Occasionally, there is sufficient space in the connectors (see FIGS. 1 and 2) to provide for one or more true shunt capacitors 5 so as to reduce the remaining effect pair of terminals, so that the terminals 0,1 represent, as I it were, a balancing network of known construction.

and made up of said shunt capacitors 5 and the small inductance segments. Thus, the self-inductance of each terminal is here divided by the shunt capacitors 5 into small inductance segments connected in series to one another. This further developmentis particularly of advantage if the terminals and l are much longer than they are thick or wide, that is to say, if they are longer than the largest dimension of the cross section of the terminal through which the direct current is fed into the module 2 through the relevant terminal. Where, as here, the terminals are much thinner than they are long, the design of the shunt capacitors 5 can be different:

The effective parasitic active self-inductance of the terminals 0 and 1 can be reduced in this further embodiment, as also in the preceding embodiments, by shunt capacitors 5 having a very high capacitance and producing for the interfering voltages a short circuit between the terminals. The terminals concerned form with the shunt capacitors 5 disposed thereat low-pass filters which smooth the current flowing therethrough.

If there is adequate space in these further embodiments, the capacitance of the capacitors and the mutual spacings thereof can also be designed such, for example, that the cut-off frequency of said low-pass filters made up of the inductance segments and shunt capacitors 5 lies higher than the highest frequencies which, according to the Fourier analysis, appear with a parasitically high energy in the interfering voltages U or U For example, provision may also be made that the characteristic impedance 8=TU of such pairs of terminals producing a balance network, where L stands for the inductance of an inductance segment and C the capacitance of the shunt capacitor 5 plus the selfcapacitance of the inductance segment, is matched through appropriate matching or accurate computation of the required capacitances of the shunt capacitors 5 to the characteristic impedance of the direct-current supply lines 6, 3 of the module 2 or to the characteristic impedance of the direct-current supply lines 8, 9 of the module rack. Due to this dimensioning of said shunt capacitors 5, the effective parasitically active selfinductance of the connector is not only reduced but, in addition, there is no reflection at the junction between the connector and the direct-current supply lines of the module or of the module rack matched thereto as a result of characteristic impedance, so that interfering voltages U U generated in the connector are very rapidly shunted into the module or the module rack because of the absence of reflections and are thereby rendered relatively harmless. In this way, the selfinductance of the pairs of terminals 7 is reduced, because the self-inductance no longer acts as a particularly large concentrated inductance and because this inductance is divided into segments partitioned by the shunt capacitors. As a result of this special dimensioning, the individual segments of the terminals act like a transmission line between two adjoining shunt capacitors 5 and have characteristics, even with respect to any interfering voltages, which do not differ substantially from the characteristics of the direct-current supply lines on the module or on the module rack. This further development is particularly of advantage if the characteristic impedence of the direct-current supply lines 3, 6 onthe module is made approximately as large as that of the direct-current supply lines 8, 9 on the module rack.

. Here, too, it is possible to provide each pair of terminals 7 on the module rack 8/9 and/or in the module 2 additionally with a high-capacity shunt capacitor 25 or 24 so that the self-inductances of the terminals of the first sort 0 are each connected in parallel with the selfinductances of the terminals of the second sort 1, referred to the interfering voltages, because the relevant capacitors then produce short circuits for these interferingvoltages. Due to the parallel connections of the self-inductances, the effective disturbingly active inductances of the connector is further reduced, thereby further diminishing the danger of disturbances in the interaction between component parts disposed on the different modules. 7 l

Frequently the direct-current supply line on the module exhibits a much smaller characteristic impedance than the direct-current supply lines 011;: the: module rack. In this case, provision can be made that even if several shunt capacitors are provided for each pair of terminals 7 (see FIG. 2), the shunt capacitor 5, 25 or 24 disposed on the plane of transition between low and high characteristic impedance is provided with such an internal resistance through adjustment or appropriate selection that the resulting resistance of a parallel connection of all these internal resistances is as large as the characteristic impedance of the direct-current supply lines disposed on the module. This further development is particularly of advantage if the characteristic impedance of the connector of the direct-current supply is matched to the characteristic impedance of the direct-current supply lines of the module rack, even if the characteristic impedance of said connector is matched to that of the direct-current supply lines on the module.

Although certain preferred embodiments of the invention have been disclosed for purposes of invention, it will be evident that various changes and modifications may be made therein without departing from the scope and spirit of the invention, whose breadth is defined solely by the appended claims.

We claim:

1. A direct-current supply connector comprising a plurality of pairs of terminals for providing electrical connection between, on the one side of said connector an elongated flat module (2) provided with a lowinductance direct-current supply line and, on the other side of said connector a module rack for receiving a plurality of said elongated modules, said module rack being connected with each of said modules over one of said connectors, current being supplied from said direct current supply line of said module rack to said module, wherein a first individual pair section of each of said terminal pairs which is connected to an outgoing line of said direct-current supply line is connected with a second pair section of said each terminal pair which is connected to a return line of the direct-current supply over a shunt capacitor disposed in the immediate vicinity of said each terminal pair.

2. The connector as set forth in claim 1, characterized by the fact that first said individual pair section carrying a signal reference potential (earth) is constructed with particularly low inductance.

3. The connector as set forth in claim 1, character- 4. The connector as set forth in claim 1 by the fact that said shunt capacitors characterized is disposed on the module rack adjacent said terminal.

5. The connector as set forth in claim 1, characterized by the fact that said first and second pair sections of said terminals are plug pins and sockets.

6. The connector as set forth in claim 1, characterized by the fact that component parts of said terminal pair disposed on said module are detachably urged against component parts of said terminal pair disposed on said module rack.

7. The connector as set forth in claim 1 wherein a component part of each of said pair sections on said module is substantially longer than the largest dimension of the cross section of said pair section terminal, characterized by the fact that at least one shunt capacitor is connected between each of said first pair sections and said second 7 pair section of said terminal pair, thereby establishing an inductance-capacitance balancing networkin said connector.

8. The connector as set forth in claim 7, characterized by the fact that said shunt capacitor is sized to match the characteristic impedance of the connector to the characteristic impedance of the direct-current supply line of the module.

9. The connector as set forth in claim 8, characterized by the fact that said shunt capacitor is sized to match the characteristic impedance of the connector to the characteristic impedance of the direct-current supply lines of the module rack.

10. The connector as set forth in claim 9, characterized by the fact that the capacitors which are provided in the connector at the junction between the characteristic impedance of the direct-current supply line of the module and the characteristic impedance of the directcurrent supply lines of the module rack have an internal resistance such that the parallel connection ,of said capacitors provide an effective resistance matching the characteristic impedance of the direct-current supply lines of the module (2). 11. The connector as set forth in claim 1, characterized by the fact that said module includes signal lines connected through said connector having terminals thinner than said terminal pair sections connected to said direct current lines.

12. The connector as set forth in claim 1, characterized by the fact that the direct-current supply line within the module is divided into a plurality of sections connected in parallel with one another, each of said sections being connected with the module rack over a plurality of said pairs of terminals. 

1. A direct-current supply connector comprising a plurality of pairs of terminals for providing electrical connection between, on the one side of said connector an elongated flat module (2) provided with a low-inductance direct-current supply line and, on the other side of said connector a module rack for receiving a plurality of said elongated modules, said module rack being connected with each of said modules over one of said connectors, current being supplied from said direct current supply linE of said module rack to said module, wherein a first individual pair section of each of said terminal pairs which is connected to an outgoing line of said direct-current supply line is connected with a second pair section of said each terminal pair which is connected to a return line of the direct-current supply over a shunt capacitor disposed in the immediate vicinity of said each terminal pair.
 2. The connector as set forth in claim 1, characterized by the fact that first said individual pair section carrying a signal reference potential (earth) is constructed with particularly low inductance.
 3. The connector as set forth in claim 1, characterized by the fact that said shunt capacitor is disposed on the module adjacent said terminal.
 4. The connector as set forth in claim 1 by the fact that said shunt capacitors characterized is disposed on the module rack adjacent said terminal.
 5. The connector as set forth in claim 1, characterized by the fact that said first and second pair sections of said terminals are plug pins and sockets.
 6. The connector as set forth in claim 1, characterized by the fact that component parts of said terminal pair disposed on said module are detachably urged against component parts of said terminal pair disposed on said module rack.
 7. The connector as set forth in claim 1 wherein a component part of each of said pair sections on said module is substantially longer than the largest dimension of the cross section of said pair section terminal, characterized by the fact that at least one shunt capacitor is connected between each of said first pair sections and said second pair section of said terminal pair, thereby establishing an inductance-capacitance balancing network in said connector.
 8. The connector as set forth in claim 7, characterized by the fact that said shunt capacitor is sized to match the characteristic impedance of the connector to the characteristic impedance of the direct-current supply line of the module.
 9. The connector as set forth in claim 8, characterized by the fact that said shunt capacitor is sized to match the characteristic impedance of the connector to the characteristic impedance of the direct-current supply lines of the module rack.
 10. The connector as set forth in claim 9, characterized by the fact that the capacitors which are provided in the connector at the junction between the characteristic impedance of the direct-current supply line of the module and the characteristic impedance of the direct-current supply lines of the module rack have an internal resistance such that the parallel connection of said capacitors provide an effective resistance matching the characteristic impedance of the direct-current supply lines of the module (2).
 11. The connector as set forth in claim 1, characterized by the fact that said module includes signal lines connected through said connector having terminals thinner than said terminal pair sections connected to said direct current lines.
 12. The connector as set forth in claim 1, characterized by the fact that the direct-current supply line within the module is divided into a plurality of sections connected in parallel with one another, each of said sections being connected with the module rack over a plurality of said pairs of terminals. 